Hanks, or Hanx as he likes to be called on social media, is known for his quirky and engaging posts on Twitter, and his post on June 2 of an imposing and mysterious New York City building left many of his followers scratching their heads.

"This is the scariest building I've ever seen! WTF goes on inside??" he wrote.

Many followers played along, making jokes about the scary, windowless building.

One user, Angel Bodnar, however, had an answer for Hanks. According to Bodnar, the building belongs to telecommunications company, AT&T, and it was "originally used to route our transatlantic com lines. Entirely full of telecom equipment."

However, according to The Intercept, the building, also known as the "Long Lines Tower," was also in use by the NSA.

"Documents obtained by The Intercept from the NSA whistleblower Edward Snowden do not explicitly name 33 Thomas Street as a surveillance facility. However — taken together with architectural plans, public records, and interviews with former AT&T employees conducted for this article — they provide compelling evidence that 33 Thomas Street has served as an NSA surveillance site, code-named TITANPOINTE," wrote Ryan Gallagher and Henrik Moltke.